Drive for speed-responsive instruments



A 1,634,565 A. F. wALLBlLLlcH Dam: Fon SPEED nsrouslvs INSTRUMENTS Filed Aug. 19. 1924 2 sheets-sheet z.

z3 6,6 f6 27 g, ,5 f/ /0 A'ITORNEYS Patented July 5, 192,7.

u 1,634,565 PATENT OFFICE.

UNITED STATES ANTHONY F.

WALLBILI'ICI-I, OF NEWARK; NEW JERSEY, ASSIGNOR TO DISTANCE-SPEED RECORDING COMPANY, vA CORPORATION OF DELAWARE. v

DRIVE FOR SPEED-RESPONSIVE INSTRUMENTS.

Appneauon ined August 19, 1924. 'serial' No. 733,013.

This invention relates to a drive mechanism for measuring instruments, and, more particularly instruments which measure the speed ot a moving vehicle or the distance traversed by it. Among such instruments are speed indicators, speed recorders, odometers and others of alike character.

Instruments of the type above referred to, used for ascertaining data as to the movement of a vehicle include moving mechanism which is driven by some part of the vehicle and thus in accordance with the vehicle movement. In speed responsive instruments, which term includes indicating and recording devices, a governor device is frequently employed, driven at a speed corresponding to the speed of rotation of some part of the vehicle which rotates at a rate depending on the surijace speed of the vehicle. Heretofore it Vhas been customary to makeuse of the angular movement of some such part as the source of power for driving the governor which accordingly assumes different positions as the vehicle speed varies. The positions assumed by the governor in turn control the movement of aA pointer. In another type of instrument, the

governor is dispensed with 'and an oil pump pumps oil through the-instrument at a rate which varies with the vvehicle speed. Ap-

propriate devices then measure the rate of liow and as in the case of the governor type, actuate mechanism by which an indicating needle is made to give a, speed reading on a scale, or a recording pen made to produce a record on a tape. n

In both types of instrument, however, and in similar instruments for measuring distance traversed and the like, the mechanism of the instrument has been driven by various devices, none of which has been altogether satisfactory .for the purpose. For instance, in speed indicators and recorders,

as used on locomotives, the instrument itself is placed in the locomotive cab and in some cases a driving pulley is mounted on the axle oi' the trailer truck and the rotation of this pulley is transmitted to the instrument by means of a cord belt drive. In other installations, instead of using a pulley so mounted, the reciprocating movement'of one of the cranks is employed, and suitable linkage is provided for transmitting this movement to the mechanism. Both of these drives depend on the angular movement of a driving member, and inaccuracies are introduced in the reading of speed given by the instrument, because as the trailer wheel, or the driving wheels of the locomotive, wear, it 'follows that the distance traversed 1n one-revolution of these wheels will vary. Consequently, as the wheels wear in use` with the consequent reductiony 'in diameter, the instrument will indicate a higher speed than that at which the locomotive is actually moving. Also, these driving devices, as a rule, are not suiiiciently rugged to stand the wear and tear of ordinary use, and in the case of the cord belt drive any slippage of the belt will result in errors in the speed reading. 'v i The object of the present invention is to provide a drive for speed-responsive instruments of the type above refered to, in whichv errors due to wear will be wholly eliminated, or else reduced to a neglible quantity, and also to provide a drive for such instruments which shall be suiliciently rugged to withstand the rough kusage to which such mechanism would ordinarily be subjected in railroad use. Inl order to eliminate the errors i introduced by thev wearing of the wheels of the vehicle, and to cause the` instrument to be driven by means which depend on the surface speed of the vehicle, rather than on the angular speed of one kof its moving parts, the present invention includes the provision of a driving wheel for-the speed measuring instrument which restsv on the tread of one of the wheels supporting the vehicle. This driving wheel is rotated by its contact with the vehicle wheel, and its rotation is transmitted ytothe speed measuring instrument through suitable connections, preferably a flexible shaft ,which gives a positive driving connection. Since the driving wheel lies directly in contactY with the tread surface of n one of the vehicle wheels, its rotation will be in direct correspondence with the'surface speed of the vehicle, and it will always rotate the same number of turns for a given movement of the vehicle, regardless of the wear of the vehicle wheel. Consequently, so long as `the driving wheel itself does not wear, the measuring instrument will be so driven that no errors can be introduced, and since the driving wheel makes a rolling contact with the surface on which it bears, wear is .greatly eliminated, and,in fact,rmay bereduced to a point at which the error introducec by thiswear is so inconsi'd'erableI asto be oino importance.

In addition to the provision of a driving wheel bearingl directly oni the tread-e of a wheel of the vehicle, theiinventxion contient plates the provision of suitable devices driven by this wheelA and in turncommunieating its rotation to the driving connection to the instrument, which are adjustable sov that thel connections may be led from the driving wheelin any direction which may be convenient, sov that if it is desired to make use of a liexibleshaft for the drivingconnection, the shaft may be led to the instru,- ment without the necessity ot making sharp bends inV it. The improved mechanism tor driving the speed-responsive instrument lends itselt particularly to use in connection with locomotives where-the driving wheel of the mechanism makes contact with the tread of one of the` main driving wheels of the locomotive. As these main driving wheels of' the locomotive are placed closely together, by mountingthe device so that the driving wheel' for the speed-responsive in strument lies between the locomotive wheelsl the device is in aprotected position and is not likely to be injured in service.

lnA the accompanying drawings, I" have illustrated one embodiment of the invention in the form which is now preferred, and in Fig,` 1' there is shown a side view ota portion of' a locomotive, largely in diagrammatic torni, showingthe speed-measuring.in# strument andits drive in one convenient location on the locomotive, Y

Fig 2 isa longitudinal cross section of the driving devicetalen' von the line 2-2 of Fig. 3,

FigB-is a topplan view oi the device, as shown in Fig2, with certain ot the parts shown in cross section,

Fig`- 4t is alongitudinal sectional' view taken on the line 4 4; of Fig. l3.

Referring now to the drawings, there is shown in Figure 2, largely in diagrammatic form, theinstallation ot a speedindicator or recorder as frequently used on locomotives. The instrument. Idesignated as 5 is mounted in any` convenient location in the cab and infillustration the drive wheel is suitably supportedona partfot the locomotive frame. in Contact. with the tread of one of' the locomotive driving. wheels. It is preferable to mountl the mechanism so that the drive wheel 6 engages the treadv of one ot'the locomotive wheels at. a point above a horizontal plane passing throughthe a-Xle of the latter andalso below the top ot the' drivinguwheel; `Thus the wheel 6 and the parts by which it issupportedlie. between the treads ot the two closely adjacent wheels, as illustrated and are in,a protectedposition. The flexible shaft''transmits the motion ott-he driving wheel to the instrument in thev usual manner. While the instrument driving' wheel 6' has beenY shown resting on the tread of a driving wheel 8, it would of course bejpossibleto mount it so that it wouldf liev in; Contact witlr the tread 0f the trailer wheel 9. it may be said in general that the drivingY wheel for the instrument will be placed so that the distance between its mountingl and the instrument will be comparatively short and it is preferable to mount the driving wheel so that the connection between it and the instrument will' not involve any considerable changesV in direction in the drivingconnection; This is, ot course, particularly important in cases` where a flexible shaft' is used.

The details ot theinstrument mechanism need' not be described in this connection, since it' is possible tor malte use ont many different instruments for t-he purpose. @ne type'of; instrument is shownin U. SL- Patent No, 1,468,426 issued tome on September- 18, 1923. On reference to'that patent it: willi-be seen that: the mechanism within the instrument casing is drivenv by means' oit/aA main shaft; which is, inl turn, drivenA through a flexible shaft by ay drivingwvheel which rewheels. By makinguse otthe-drivingfwheel which rests on the tread? ot` the vehicle wheel, the speed responsive instrument is driven in correspondence with the surface speed ot; the vehicle and the angular speed otamoving partf ot the vehiclefis notrelied on as has heretoforey been customary. As previously explained, when thel drive-A depends on the angular motionot' apart ot' the vehicle thenthe wearing ot this part will introduce errors inthe speed' and`l` distance readingof the instrument, but inthe present typeof drive theeiilectl is the same as-it'fthe driving wheel 6 -were lyingf in- Contact with the groundand the rate-otrotationof this driving wheel'will'dependaltogether on the speed atwhich thevehiclen'ioves over the ground. Any wear in the locomotive driving wheelfcannot atleet the -readingof the instrument and the onlyae-rror that can be introduced willf develop from wear ofi the wheelG or' else from slippaoeofthiswheel Gon the locomotive wheellS: As-willpresently be-describech these errorsmay 'bereadi ilykept' at a-minimum-v The inea-ns by which l the vdriving wheel'v 6 is supportedandhelcl in contactwith the tread of 'the wheel 8', is sli'ewnlin the remainingl figures ofithe drawings. This support` ing means includes a# bracket 10 which is boltedor Aotherwise secured'to a stationary part of zthe-locomotive such as the frameot the latter. Preferablyv the bracket 10 is secured-to the trame-in such position that the drive whecllies between the treads otfthe closely adjacentldriv-ing wheels of theA locomotiv-e. At one'end the bracketis forked fili Vceives its mot-ion trom one oi the vehicle lUS lll)

Cil

` point of the housing 17.

and across the arms 11, so provided, extends a pivot pin 12. The wheel 6 is carried in the end of an arm 13 the other end of which terminates in a boss 14C through whichthe pin.

12 extends. The arm' 13 is secured to the pin 12 by means of a setscrew 15, andas the pin 12 is free to move in the forked end of the bracket 10, the arm 13 can swing about the pin as an axis. Y

At its forward end the arm 13 terminates in spaced arms 16 and a gear housing 17 which is generally cylindrical in form is supported at its ends in the arms 16. As shown more clearly in Figure 4l, the arms 16 have central semicircular recesses 18 to receive the housing 17 and avcap member 19 held in place by bolts 20 which enterk the ends of the arms 16 serves to hold each end of the housing 17 in place with reference to the arms 16. These cap members vmay be loosened so as to permit the housing 17 to be placed in any angular position relative to the main arm 13. lVhen placed in the proper position of adjustment the bolts 2O may be drawn tight and the housing will then be held in adjusted position against movement. lVthin the housing is a shaft 21 provided with a worm 22 intermediate its ends, the worm lying substantially at the central The shaft 21 is supported within a housing by means of roller bearings 23 and 24 ofV appropriate design and one end of the shaft extends beyond the housing and carries the drive wheel 6 which is suitably keyed to the shaft; The drive wheel 6 is held in position on the shaft by means of a nut 25 and the shaft 21 carries a nut 26 atl its other end so that the shaft may be secured against axial movement relative to the housing. In order to permit its removal, the housing is cut away at one end, as at 27, and this open end of the housing is covered by a plate 28 which is secured in position by screws. The inner face of the wheel 6 is recessed, as at 29, to receive a felt washer which prevents the escape of lubricant from the housing.

Referring now to Figure 2, it will be seen that the housing has an off-set boss 30, along one side, and mounted in this boss in any appropriate manner is a shaft 31 which carries a worm wheel 32 meshing with the worm 22. The shaft 31 is supported in the boss within a sleeve 33 the end of which terminate beyond the face of the boss in a threaded enlargement 34. At the other end of the hollow shaft is an oil passage 35 communicating with the interior of the casing and an oil cup 36 is mounted in the boss in such position as to' deliver its contents to the interior of the casing through the passage. The shaft 31 has a recess 37 at its forward end and in this recess is a locking plate 38. The end link 39 of a round flexible shaft has a flattened portion ysmall as to be of no importance.

contact with the tread of the locomotive wheel 8 by means of a spring Ll1, one end of which is secured to the arm near its end, while the other end of the spring is secured to some-,fixed part of the locomotive.

By mounting' the driving wheel on a fixed support which is capable of being swung so that the uwheel may accommodate itself to the Vmovements of the locomotive wheel with reference to the frame, any slippage be tween the driving wheel and the locomotive wheel has been Llargely eliminated, at least the error introduced from this source is so In addition to the elimination of this error, any error which might be introduced by the wearing of the driving wheel 6 may be eliminated by making .that wheel with a hard tread. For instance, it will be noted that the wheel is in the form of a circular web having an enlarged tread surface.v The web is preferably made ofsoft steel and the tread of some alloy steel, such as a vanadium steel. siderable extent under any. conditions because of the fact that it has a rolling contactwith the tread of the locomotive wheel 8, but by making its rim of some material such as that referred to, its circumference will remain substantially constant for long periods of time. Also, this driving wheel 6 is quite inexpensive and it may be cheaply and readily replaced whenever conditions re-V quire.

The present drive mechanism also affords numerous advantages, among which may be mentioned the fact that the readings of the speed -indicating or recording instrument may be quickly converted from miles to kilometers and vice-versa, without Aany alterations in the mechanism itself For this purpose it is only necessary to substitute a suitab-le driving wheel 6, the worm and worm wheel for which have been selected to produce the desired result.y Such an alteration in the use of the instrument consequently does not require any alterations in its mechanism, but simply necessitates the substitution of certain parts in the drive mechanism.

As previously explained, it is customary and desirable to use a flexible shaft connection between the instrument in the. cab and the driving wheel 6. Such flexible This tread will not wear to any con- L shaft should always be led from the driving Y wheel to the instrument with as few bends as possible and these bends should also be made with as large a radius as possible. The present drive mechanism makes it possible to arrive` at the desired4 condition with greatv ease because after the bracket l-O has been secured in place,4 and the driving Wheel Gput in Contact with the tread of the vehicle on which it is to'rung, then the housing L7 can be adjusted in any position which is required so that the end oi: the drive shaft 3l' will point in any desired direction; Thus,` this adjustment permits the adjustable shaft to be led directly to the instrument with' few bends` and' these bends-may bemade on as large'a4 radius` as may be desirable.- While I have' described the new driving mechanism inir connection with speed indicator and' recorder, it' will be understood that it is appropriate for use in connection with many other instruments; as for' instance, tlio-se which measure or record distance trav'ersed Also its use is by no means limitedr to locomotives,v but it has been designed purposely so as tobe suili oientiy strongiand rugged 'for railroad use. and itwill be seen 'from a consideration-of the' drawings and the description that the drive mechanism' is comparativ'ely simple and cheap to construct7 and there are rio parts which \\'ould`=\vear quickly. Furthermor'e, it does not require any considera'be adjustment or attention in use and will operate satisfactorily i'or indeiiniteperiods.

By mounting the device inthe manner shown, thebracket may be secured to a portion` of tlie frame of the locomotive, and the arm plvotally securedV to the bracket extends into the spacey between the two adjacent drive Wheels of the locomotive. The wheel 6 thus bears' against the tread oi' one oiy these drive wheels at' a point beyond' the top oi' the drive Wheel and above a horizontal plane through the axle. The mechanism is thus in protected posit-ionl A device for driving` an instrument 'for indicating the speed of a nio-vingvehicle, comprising" the combination of a Vsupport secured=to a fixed part of the vehicle, an arm pivotallymounted on the support5 this arm terminating in forked ends a housing car-A ried by the' support, a shaft rotatably mountedy in the housing, a Wheel carried by the shaft beyond the housing and adapted to lie in contact with the tread of one of the vehicle Wheels 'to be rotated thereby as thc' vehicle moves, a secondary shaft Withinthc housing driven by they rs't shaft and con nected to the spe'ed-res'ponsive:mechanism` and a device for lubricating the secondary shaft* securedl to the housingv and' lying,` in the space betweenY the forked ends ot the arm in which the Ahousingis mounted. Y

In testimony whereof I atliX niy signature.

ANTHGNY F. VALLBILLICH. 

